Constant pressure wringer



March so, 1943. L. F. I -IAM MAND 2,314,980

' CONSTANT PRESSURE WRINGER Filed March 25, 1940 3' Sheets-Sheep lMar'chso, 1943. L. F. HAMMAND $314,980

I CONSTANT PRESSURE WRINGER Filed March 25, 1940 s Sheets-Shet 2Patented Mar. 30, 1943 UNETED STATES ATENT OFFICE 2,314,980 CONSTANTPRESSURE WRINGER Lowell F. Hammand, Chicago, Ill., assignor to NicholasL. Etten, Waterloo, Iowa 11 Claim The present invention relates toclothes wringers and more particularly to mechanism for controlling thepressure exerted between the wringer rolls.

The principal object of the invention is to provide pressure controldevices for a wringer such that the wringer rolls may operate undercustomary pressures at all times during the normal operation of thewringer and will operate under greatly diminished pressure whenever thepressure rolls are forced apart into abnormal spaced relationship.

Another object of the present invention is to provide wringer pressurecontrol devices comprising a triangular lever operativelyinterconnecting a fiat leaf type wringer spring with the movable roll ofthe wringer.

A further object of the invention is to pro vide a wringer pressurecontrol mechanism adapted to cause the pressure rolls to operate underundiminished wringing pressure in normal displacement of the IOlls andto operate under greatly diminished wringing pressure whenever thewringer rolls are moved into abnormal spaced relationship.

Another object of the invention is to provide wringer pressure controldevices constituting the triangular lever mounted for free floatingmovement to permit straight line vertical movement of the wringer rollbearings and to shift the effective point of spring pressure applicationon the lever.

A further object of the invention is to provide wringer pressure controldevices of extreme simplicity and rugged construction adapted to be usedin any one of the conventional wringer structures now commonly in useand capable of great economy in manufacture.

Further objects will appear hereinafter.

In the prior art numerous attempts have been made to construct a wringerequipped with pressure control devices whereby the pressure effectivebetween the wringer rolls would not rise to great extremes in the eventthat the rolls were forced apart into an abnormal-spaced relationship,but insofar as is known to the applicant, these prior art devices havebeen Objectionable on the ground that they have been inherentlycomplicated, expensive to manufacture and unreliable in operation. 7

In the present invention the desired results have been obtained by thesimple expedient of mounting a free-floating triangular lever betweeneach of the bearing blocks of the movable wringer roll and the pressurespring of the wringer.

The arrangement is such that the wringer bearing blocks may move in astraight line vertical direction and this movement will be effective toshift the three operating points of the lever with respect to each otherin such a manner as to vary the mechanical advantage existing betweenthe pressure spring of the wringer and the movable wringer roll. 'Itwill be obvious that in such an arrangement the exact dimensions of thelever may be varied in accordance with the requirements of eachindividual wringer to provide a pressure control device having the exactmechanical characteristics preferred.

In the preferred construction of the invention the arrangement is suchthat one of the operating points of the triangular lever is shiftablewith respect to the pressure spring and it is, therefore, possible toform a cam surface on the pressure spring in order that any desiredmechanical characteristics may be obtained in the mechanism as a whole.

Referring more particularly to the drawings:

Fig. 1 is a longitudinal'sectional view of a characteristic type ofwringer constructed in accordance with the principles of this invention;

Fig. 2 is a detail sectional view of the pressure control mechanisms inthe position they assume during the normal lateral displacement of thepressure rolls caused by the thickness of the materials being passedbetween the rolls;

Fig. 3 is a detail sectional view similar to Fig. 2, illustrating theposition the mechanisms assume when the pressure rolls are forced intoabnormal spaced relationship with each other;

Fig. 4 is a detail sectional view similar to Fig. 2, illustrating theposition the pressure mechanisms assume when the pressure rolls aremoved into extreme spaced relationship with each other;

Fig. 5 is a detail sectional view illustrating a modified form or thepressure control devices;

Fig. 6 is a fragmental detail sectional view of another modified form ofpressure control mechanism; and

Fig. 7 is a perspective view of one of the triangular lever pressurecontrol devices.

The wringer chosen for purpose of illustration' of the principles ofthis invention comprises in general a main frame iii incl ning a pair ofvertical bearing slideways ll and I2 rigidly interconnected at theirlower extremities by a longitudinal bottom channel member l3 spot weldedor otherwise secured to the vertical bearing slideways H and I2. The topframe Mof the wringer may be secured to the main frame L0 in any c nv aa ne a or exam le. by e lower wringer roll 23 by means of a spur gear24;

which is adapted to mesh with an internal gear 25 pinned to the lowerroll shaft 22. The lower roll shaft 22 is, of course, journaled forrotation in suitable bearings 26 and 21 carried in the vertical bearingslideways II and I2, respectively. It will be seen from reference toFig. 1 that the bearing 26 is stationarily mounted and is secured inposition by the cross pin 28, while the bearing 21 is free for verticalmovement limited by the lower bearing support 29 and the cross pin 3|,and is urged upwardly by a light coiled spring 32. The

arrangement is such that whenever the upper roll 33 is forced downwardlyinto pressure relationship with the lower roll 23, the coil spring 32will be compressed until the movable bearing 21 seats firmly on thelower bearing support 29. In this position the internal gear 25 will bein the position illustrated in the drawings and will be in mesh with thespur gear 24 carriedby the power drive shaft 2| to complete a rotarydriving connection between the power head l6 and the lower wringer roll23. When the pressure between the rolls 33 and 23 is released, however,the coil spring 32 will act to move the bearing 21 upwardly until thelower roll shaft 22 engages the cross pin 3|. In this position theinternal gear 25 and the driving spur gear 2| will be in concentricrelationship and since the extreme outer diameter of the spur gear 2| isless than the inside diameter of the internal gear 25, these gears willnot engage and the gear 2| may continue to rotate without imparting anymotion whatsoever to the wringer rolls.

The upper wringer roll 33 includes a roll shaft 34 j ournaled at eachend of the wringer in similar bearings 35 mounted for vertical movementin the bearing slideways H and I2. Each of the bearings 35 is providedwith a clip 38 by which the bearing 35 is mounted on a cross pin 31extending between a pair of triangular plates 38 which cooperate to actas a triangular lever 38 interconnecting the roll bearings 35 with aflat leaf pressure spring 39 adjustably mounted on the top frame M ofthe wringer by means of a threaded adjustment screw 4|.

The operative connection between the pressure spring 39 and thetriangular lever assembly 38 is completed by means of a roller 42rotatably mounted on a cross pin 43 riveted at each end to one of thetriangular plates 38' and adapted to be engaged by the cam surface 44 ofthe end portion of the flat leaf pressure spring 39. p

A movable fulcrum is'provided for the triangular lever assembly bymounting a pair of links 41 on rivets 48 secured in the side walls ofthe top frame l4 and pivotally interconnecting the lower ends of each ofthese links 41 to one of the-triangular plates 38 by means of a pair ofrivets 49. This arrangement provides a full floating triangular lever tooperatively interconnect the pres sure spring 39 of the wringer witheach end of the movable pressure roll 33. The term full floating as usedhere is intended to define a lever having no fixed mounting point, sothat all points of the lever are movable with respect to the wringerframe.

When the top frame l4 of the wringer is secured in operative position onthe main frame l8, the cam surface 44 at either end of the spring 39will bear downwardly against rollers 42 of the triangular levers 38 andwill cause each of these levers 38 to tend to pivot downwardly aroundthe fulcrum 49 so that the cross pins 31 will xert downward force on theupper roll bearings 33 and maintain the upper roll 33 in a predeterminedpressure relationship with the lower roll 23. It will be understood, ofcourse, that the initial degree of pressure existing between the tworolls 33 and 23 will be adjustable by means of the threaded adjustingscrew 4|, but that in the operation of V the machine the triangularlevers 38 will also act to control the operating pressure whenever therolls are forced apart by the thickness of the work passing betweenthem. In the normal operation of the machine this relative spacingmovement between the rolls will be relatively small, probably notexceeding one-half inch under normal conditions. Within this range ofmovement it is often desirable to provide pressure control devices ofsuch design thatas the rolls are urged apart the pressure will increaseslightly. This arrangement accomplishes .a highly desirable result inthat it provides a light operating pressure when thin articles, such ashandkerchiefs, are being passed between the rolls, and graduallyincreases the pressure when heavier articles, as sheets and blankets,are passing through the wringer. In the present device this increase ofpressure in the operating range of the wringer is accomplished byproviding the cam surface 44 on each end of the flat leaf type pressurespring 39, such that the initial movement of the triangular levers 38will cause the rollers 42 to act on the cam surfaces 44 and cause acomparatively large degree of flexing of the spring 39. This arrangementprovides means to increase the pressure exerted by the leaf spring 39,but since the triangular levers 38 have shifted in position, asillustrated in Fig. 2, the mechanical advantage between the spring andthe roll have been somewhat altered and, if desired, the cam surface 44may be cut at such an angle that these two factors compensate for eachother, and the wringer pressure will remain constant during the normalrange of displacement of the upper roll. Such an arrangement isillustrated in Fig. 5, to be described hereafter.

In an emergency, as, for example, in the event that the operator shouldallow her arm to get between the wringer rolls, it is obvious that therolls will be forced apart a distance greater than the normal spacing atwhich the rolls operate. In this event, it will be readily apparent thatit is desirable not only that the wringing pressure does not increase tothe great extremes encountered in some present-day wringers, but it isalso desirable that the pressures be greatly diminished to avoid seriousinjury insofar as it is possible to do so. The manner in which this isaccomplished in the present device is illustrated in Fig. 3, where itwill be seen that the roll 42 constituting the center point of thetriangular lever 38 has been shifted longitudinally along the spring 39and the lever 38 has shifted to sharply alter the mechanical advantagesexisting between the spring and rolls, so that the effective pressurebetween the rolls 33 and 23 has been reduced almost to zero. V

' In the event that the rolls 33 and 23 are forced apart to theirextreme spaced relationship illustrated in Fig. 4, the roller 42 willmove inwardly until it crosses the center line between the rivets 48 andthe rivets 49. this position, the forc of the pressure spring 39 will berestrained by the links M and will exert no force whatever tending tourge the rolls into engagement. The upper roll 33 will, therefore, beretained in locked position out of engagement with the lower roll 23.

In the modified form of the invention illustrated in Fig. 5, thepressure control mechanism has been arranged to act on the lower roll ofthe wringer rather than on the upper roll, as in the preferred form ofthe invention just described. The structure illustrated in Fig. includesa pair of Vertical bearing slideways 51 joined at theirlower ends bycross frame 52 and their upper ends by a top frame 53 releasably latchedto theslideways 5| by means of a latch 54, a link 55 and a reset lever55. The structure is quite similar to the arrangement illustrated inFig. 1, except that the upper wringer roll 51 is mounted in stationarybearings 58, each of which is locked in position in the bearingslideways 5| by a cross pin 59, which extends through a slot 6| in thesidewall 52 of the slideway and is riveted in the wall of the top frame53. The lower roll 63 is journaled for rotation in a pair of bearings 68mounted for vertical slidin movement in the slideways 5i and urgedupwardly by a flat pressure spring 5% mounted on a rigid bracket 55positioned at substantially the mid-point of the lower cross frame 52.comprises a triangular lever 66 mounted on a fixed pivot point 6! rivetein the walls of the lower cross frame 52. This lever 66 is preferably,though not necessarily, made up of a pair of identical plates spacedapart on opposite sides of the spring es. The spring 64 bears againstthe roller 68 mounted on the rivet 59 and forces the lower roll $3upwardly by means of the connection established by the link H extendingbetween the pin 12 on the lower roll bearing BE and the pin '!3 on thetriangular lever 65. The operation of this pressure control device issubstantially the same as the operation of the mechanism illustrated inFig. 1, except that the cam surface 14 on the end of the spring 6% iscut at an angle calculated to compensate for the change of mechanicaladvantage that takes place during the movement of the lever 66 throughits operating range and thus maintains the constant pressure between therolls 5'! and 63 until these rolls are moved apart a distance greaterthan the normal range of operation of the device.

It will also be noted that the spring 54 is mounted on a rigid andstationary supporting bracket 65 which will prevent any rocking movementof the spring at its point of support and cause each end of the roll 53and spring 64 to operate independently of the other.

The second modified form of the invention is illustrated in Fig. 6. Inthis modification a triangular lever Si is mounted on a fulcrum 82suspended from the supporting rivet 83 by the link 84. The roll bearing85 is mounted on the cross pin 86 and a roller 81 is mounted on thecross pin 88 and adapted to be engaged by the spring 89. The principaldifference between this structure and the structure illustrated in Fig.1, is that the lever 81 comprises a lever of the second class; that is,a lever wherein the point of application of the force to the bearing isbetween the fulcrum andthe point of application of the spring pres- Whenthe parts assume The pressure control device in this wringer sure,whereas the lever illustrated in Fig. 1, comprises a lever of the thirdclass, wherein the point" of application of the spring pressure isbetween the fulcrum and the point of application of the bearingpressure.

' The operation of the mechanisms is substantially the same, however,with the single exception that no cam surface has been provided on thespring 8d so that the leverage existing between the spring and roll isentirely dependent on the dimensions of the lever ill. The result ofthis structure, of course, is that the effective pressure between thewringer rolls will begin to decrease immediately as the rolls begin tomove apart as contrasted with the structure illusrated in Fig. 1, inwhich there is a slight increase in pressure and in contrast with thestructure illustrated in Fig. 5, where the pressure remains. f constant.

From the foregoing description it will be ap parent that bypracticingthe principles of thisinvention the operating pressure of a conventionaltype of wringer may be controlled by mechanism of an exceedingly simpleand rugged nature. Furthermore, it will be seen that the mechanism hereillustrated and described is of such a nature that it may be easilyincorporated into the design of the conventional type of wringer now incommon use in the industry since the principal parts of the wringerstructure, namely, the rolls, the main frame, the top frame. the powerhead'the pressure release and reset mechanism, and the roll stopmechanism may be constructed exactly as they have been constructed inthe prior art, and the pressure control devices comprising thetriangular levers and links may be incorporated into almost any modernwringer without the necessity of altering the general appearance oroperation of the wrmger.

it will also be seen that the lever and link pressure control mechanismsperform an incidental function at the time when-the emergency releasemechanism of the Wringer is operated in that. they act as limit links toprevent the top frame from being thrown too far upwardly when theemergency pressure release is operate While I have shown and described apreferred embodiment of this invention in compliance with thepatentstatutes, I am aware that it is subject to numerous modificationsand alterations without. departing from the invention spirit and Itherefore do not wish to be limited except by the scope of theappendedclaims.

I claim: 7

1. In a wringer, a frame, a laterally rnovable pressure roll, a fiatleaf pressure spring adapted to exert force acting at substantiallyright angles to the axis'of said roll; and pressure control mechanismsoperatively interconnecting said spring with said roll at each end ofsaid roll, each of said pressure control mechanisms comprising an anchorconnection on the frame, a pivotal connection anchored to the roll, anda link and triangular lever of the third class pivotally interconnectingeach other and extending between the pivotal anchor connection on theframe and the pivotal connection anchored to said pressure roll, saidlever being adapted to operatively engage a cam surface formed on saidspring, said pressure control mechanisms being characterized by meansresponsive to normal lateral displacement of said movable roll to exertundiminished pressure between the wringer rolls, means responsivetoabnormal lateral displacement oxfsaid movable roll to diminish theeffective pressure between the rolls, and means responsive to maximumlateral displacement of the movable roll to maintain the wringer rollsin spaced-apart relationship.

2. In a wringer, a frame, a laterally movable pressure roll, a flat leafpressure spring adapted to exert force acting at substantially rightangles to the axis of said roll; and pressure control mechanismsoperatively interconnecting said spring with said roll at each end ofsaid roll, each of said pressure control mechanisms comprising an anchorconnection on the frame, a pivotal connection anchored to the roll, anda link and triangular lever of the third class pivotally interconnectingeach other and extending between the pivotal anchor connection on theframe and the pivotal connection anchored to said pressure roll, saidlever being adapted to operatively engage a cam surface formed on saidspring, said pressure control mechanisms being characterized by meansresponsive to normal lateral displace" ment of said movable roll toexert undiminished pressure between the wringer rolls, and meansresponsive to abnormal lateral displacement of said movable roll todiminish the effective pressure between the rolls.

3. In a wringer, a frame, a laterally movable pressure roll, a flat leafpressure spring adapted to exert force acting at substantially rightangles to the axis of said roll; and pressure control mechanismsoperatively interconnecting said spring with said roll at each end ofsaid roll, each of said pressure control mechanisms comprising an anchorconnection on the frame, a pivotal connection anchored to the roll, anda triangular lever having an end fulcrum extending between the pivotalanchor connection and the pivotal connection anchored to said pressureroll; said pressure control mechanisms being characterized by meansresponsive to normal lateral displacement of said movable roll to exertincreasing pressure between the wringer rolls, means responsive toabnormal lateral displacement of said movable roll to diminish theeffective pressure between the rolls, and means responsive to maximumlateral displacement of the movable roll to maintain the wringer rollsin spaced-apart relationship.

4. In a wringer, a frame, a laterally movable pressure roll, a fiat leafpressure spring adapted to exert force acting at substantially rightangles to the axis of said roll; and pressure control mechanismsoperatively interconnecting said spring with said roll at each end ofsaid roll, each of said pressure control mechanisms comprising an anchorconnection on the frame, a pivotal connection anchored to the roll, anda triangular lever of the third class extending between the pivotalanchor connection and the pivotal connection anchored to said pressureroll, said pressure control mechanisms being characterized by meansresponsive to normal lateral displacement of said movable roll to exertincreasing pressure between the wringer rolls and means responsive toabnormal lateral displacement of said movable roll to diminish theeffective pressure between the rolls.

5. In a wringer including a main frame, a top frame, a latchinterconnecting said main and top frames, a manually operable latchrelease, and a reset lever, the combination of a plurality of pressurerolls including a movable roll mounted in bearings for movement in adirection lateral to the roll axis, spring means associated with saidmovable roll, and pressure control mechanisms operativelyinterconnecting said spring means and said roll; said pressure controlmechanisms being characterized by means to maintain predeterminedinitial operating pressure between said pressure rolls when said rollsare in contact, means responsive to normal lateral displacement of saidmovable roll to exert undiminished pressure between said rolls, andmeans responsive to abnormal lateral displacement of said movable rollto gradually and progressively diminish the effective pressure betweensaid rolls.

6. In a wringer including a frame, a plurality of pressure rolls, and aflat leaf pressure spring adapted to exert force acting at substantiallyright angles to the axes of said rolls, pressure control mechanismsinterconnecting said spring and said rolls at each end of one of saidrolls, each of said pressure control mechanisms comprising a triangularlever of the third class including a point of force application withsaid spring, and means to shift said point of force application betweensaid lever and said spring in response to lateral displacement of one ofsaid rolls.

7. In a wringer including a frame, a plurality of pressure rolls, and apressure spring, pressure control mechanisms interconnecting said springand said rolls at each end of one of said rolls, each of said pressurecontrol mechanisms comprising a triangular lever of the third class, apoint of engagement between said lever and said spring, and means toshift said point of engagement between said lever and said spring inresponse to lateral displacement of one of said rolls,

8. In a wringer including a frame, a plurality of pressure rolls, and afiat leaf pressure spring adapted to exert force acting at substantiallyright angles to the axes of said rolls, pressure control mechanismsinterconnecting said spring and said rolls at each end of one of saidrolls, each of said pressure control mechanisms comprising a triangularlever having an end fulcrum including a point of engagement with saidspring, and mounting means for said lever adapted to shift said point ofengagement longitudinally of said spring in response to lateraldisplacement of one of said rolls.

9. In a wringer comprising a frame, a spring,'

and a plurality of pressure rolls including a laterally displaceableroll and movable bearings for said roll, pressure control devicesoperatively interconnecting each end of said spring with one of saidmovable bearings, each of said pressure control devices comprising ananchor connection on the frame, a pivotal connection anchored to themovable roll bearing and a link and a floating triangular lever of thethird class pivotally interconnected with each other and extendingbetween the pivotal connection on the frame and the pivotal connectionon the movable roll bearing; and a point of force applicationoperatively interconnecting said floating triangular lever and saidspring.

10. In a wringer comprising a frame, a spring, and a plurality ofpressure rolls including a laterally displaceable roll and movablebearings for said roll, pressure control devices operativelyinterconnecting each end of said spring with one of said movablebearings, each of said pressure control devices comprising a triangularlever of the second class, a pivotal anchor connection on the frame, apivotal connection with the movable roll bearings, and a shiftable pointof force application between said lever and the pressure spring.

11. In a wringer including a frame, a plurality of pressure rolls and apressure spring, pressure control mechanisms interconnecting said springand said rolls at each end of one of said rolls, each of said pressurecontrol mechanisms comprising a-triangular lever of the second class, apoint of engagement between said lever and said spring, and a means toshift said point of engagement between said lever and said spring inresponse to lateral displacement of one of said rolls.

LOWELL F. I-IAMMAND.

